In the case of Boston and Maine Railroad v. Hooker (1913), the U.S. Supreme Court was asked to determine whether a state law could require railroads to install safety devices on their trains, or if this constituted an infringement upon interstate commerce regulations set by Congress. The New Hampshire legislature had passed a law requiring all trains operating within its borders to be equipped with automatic couplers and air brakes for safety reasons. The Boston & Maine Railroad argued that such legislation interfered with interstate commerce, which is under federal jurisdiction according to the Constitution's Commerce Clause. The court ruled in favor of Hooker, upholding the state law as constitutional because it did not directly regulate interstate commerce but instead focused on promoting public safety - a legitimate exercise of police power by states over matters within their boundaries. This decision affirmed that while Congress has exclusive authority over regulating interstate trade, states can enact laws affecting local aspects of such trade provided they do not conflict with federal statutes or unduly burden interstate commerce.

In the dissenting opinion for Boston and Maine Railroad v. Hooker, Justice Holmes disagreed with the majority's decision that New Hampshire's law requiring railroads to maintain fences along their tracks was unconstitutional. He argued that states should have the power to regulate businesses within their borders as long as they do not interfere with interstate commerce or violate any other constitutional provisions. According to him, this case did not involve either of these issues; instead it was a matter of safety regulation which falls under state police powers. Furthermore, he contended that if there were any burdens on interstate commerce due to this law, they were incidental and outweighed by its benefits in terms of preventing accidents and protecting public safety.